Overall network (GVN) function

P00.19-3774-09

Illustrated on model 203.0

A1 Instrument cluster

A2 Radio (with code (523) MB Audio 20 radio, without code (529) HIGH Class Japan, without code (530) COMAND APS USA (with navigation system))

A2/6 CD player with changer (in glove box) (for code (819) 6-disk CD changer)

A2/13 Sound amplifier
(with code (810) Sound system)

A2/56 Radio and navigation unit (for code (525) MB Audio 50 APS radio)

A6n1 STH control unit
(with code (228) Stationary heater)

A35/1 Hands-free system control unit (only )

N3/10 ME-SFI [ME] control unit
(with gasoline engine)

N10/1 Front SAM control unit with fuse and relay module

N10/2 Rear SAM control unit with fuse and relay module

N15/3 ETC control unit
(with transmission 722.6)

N15/5 Electronic selector lever module control unit
(with transmission 722)

N22 AAC control and operating unit (without code (581) Comfort automatic air conditioning)

N22/7 Comfort AC control and operating unit (with code (581) Comfort automatic air conditioning)

A35/11 Voice control system control unit (with code (813) Voice control system (VCS [SBS]))

A40/3 COMAND operating, display and controller unit (with code (527) COMAND APS with single DVD drive (with navigation system) or with code (529) HIGH Class Japan or with code (530) COMAND APS USA (with navigation system))

N2/7 Restraint systems control unit

N2/13 WSS (Weight Sensing System) control unit (only )

N3/9 CDI control unit
(with diesel engine)

N26/9 Special vehicle multifunction control unit (SVMCU [MSS])
(for special-purpose vehicles)

N28/1 Trailer recognition control unit (with code (550) trailer hitch)

N32/1 Driver-side front seat adjustment control module with memory (with code (275) driver seat, steering column and electrically adjustable outside mirror with memory)

N32/2 Passenger-side front seat adjustment control unit with memory (with code (242) Electrically adjustable front passenger seat with memory)

N80 Steering column module

N87/5 SDAR control unit (with code (536) SIRIUS satellite radio)

N93 Central gateway control unit (up to 27.7.04)

N93/1 Audio gateway control unit
(with code (529) HIGH Class Japan)

N123/1 UPCI (Universal Portable CTEL Interface) control unit (with code (386) Preinstallation for telephone "Handy", UPCI system)

N123/4 Emergency call system control unit
(only )

Y3/8n4 Fully integrated transmission control (VGS) control unit
(with transmission 722.9)

N47-5 ESP and BAS control unit

N62 PTS control unit (with code (220) Parktronic system (PTS))

N69/1 Door control unit front left

N69/2 Door control unit front right

N69/3 Left rear door control unit
(model 203.0/2)

N69/4 Right rear door control unit
(model 203.0/2)

N70 Overhead control panel control unit

N72 Lower control panel control unit (with code (228) Stationary heater or for special-purpose vehicles)

N72/1 Upper control panel control unit

N73 EIS [EZS] control unit

General overall network

Controller Area Network (data bus/CAN bus) (CAN):

The CAN is an electrical bus system for the transmission of data on two lines.

The CAN consists of a twisted two-core data line that connects all subscribers (control units) via a parallel connection. The two lines of the data line must not be swapped (low level/high level).

Each connected control unit is able to transmit or receive data (bidirectional bus). The data is transmitted digitally at various intervals. The individual data blocks are defined in a data protocol and it is specified which data are received or transmitted by a control unit.

The sum of the data blocks, the short break between two transmission intervals and other properties are checked constantly. Detected faults are stored and placed in the fault memory.

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The CAN offers the following advantages:

 Data exchange between individual control units

 Readying sensor signals for several systems

 Reducing the number of electrical lines

 Improving the electromagnetic compatibility (EMC)

The following CAN systems are involved in the network:

 Controller Area Network bus class B (interior compartment) (CAN-B)

 Controller Area Network bus, class C (engine compartment) (CAN-C)

 Controller Area Network bus class D (diagnosis) (CAN-D)

Media Oriented System Transport (MOST):

MOST is a networking system comprising a fiber optic cable that makes use of optical information transfer. With this system, data are transferred by light pulses. They are transmitted to the components connected to the MOST (e.g. audio components). The light pulses are then reconverted into electric signals in the receiver component.

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Due to its high transfer rate, the MOST can simultaneously transmit source data (music, video, voice, etc.) and check data (commands, instructions, etc.) without compromising the information content.

The MOST offers the following advantages:

 Extremely high data transfer rate

 Prevents tapping and crosstalk

 Data transmission is not sensitive to electromagnetic radiation

 Short-circuit resistance

 Potential-free connection of the MOST ring subscribers

 No oxidation

 Low weight of fiber optic cable

 Small line diameter

 Moreover, various components are connected to the control units via local interconnect network (LIN). More information on these connections can be found in the corresponding function descriptions.

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CAN-B

The CAN-B is responsible for data transfers in the vehicle interior. It interconnects the different systems that can be operated by the driver or the front passenger (e.g. power windows, interior air conditioning). The CAN-B operates at a transfer rate of
83.3 kbits/s.

The following control units are connected to CAN-B:

 Instrument cluster

 Radio or COMAND

 STH control unit

 Restraint systems control unit

 WSS control unit

 front SAM control unit

 Rear SAM control unit

 AAC control and operating unit or comfort AAC control and operating unit

 Special vehicle multifunction control unit (SVMCM)

 Trailer recognition control unit

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 Driver front seat adjustment control unit with memory

 Front passenger front seat adjustment control unit with memory

 PTS control unit

 Door control unit front left

 Door control unit front right

 Door control unit rear left

 Door control unit rear right

 Overhead control panel control unit

 Lower control panel control unit

 Upper control panel control unit

 EIS [EZS] control unit

 Steering column module

 Central gateway control unit

 Audio gateway control unit

Gateways:

The following control units form interfaces for the data exchange between CAN-B and other bus systems:

 EIS [EZS] control unit or central gateway control unit
(interface to CAN-C and CAN-D)

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 Radio, COMAND or audio gateway control unit
(interface to MOST)

CAN-C

CAN-C is responsible for data transfers for the drive and chassis systems. The CAN-C operates at a transfer rate of 500 kbits/s.

The following control units are connected to CAN-C:

 Instrument cluster

 CDI control unit or ME-SFI [ME] control unit

 ECU [EGS] control unit or fully integrated transmission control control unit

 Electronic selector lever module control unit

 ESP and BAS control unit

 EIS [EZS] control unit

 Central gateway control unit

 Steering column module

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Gateways:

The following control units form interfaces for the data exchange between CAN-C and other bus systems:

 EIS [EZS] control unit or central gateway control unit
(interface to CAN-B and CAN-D)

CAN-D

An external tester (e.g. STAR DIAGNOSIS) can be connected via CAN-D. Furthermore, it is responsible for the data transfer of the emergency call system control unit.

The CAN-D operates at a transfer rate of 500 kbits/s.

The following control units are connected to CAN-D:

 EIS [EZS] control unit or central gateway control unit

 Emergency call system control unit

 External tester (e.g. STAR DIAGNOSIS)

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Gateways:

The following control units form interfaces for the data exchange between CAN-D and other bus systems:

 EIS [EZS] control unit or central gateway control unit
(interface to CAN-B and CAN-C)

MOST

MOST is an optical networking system. Here, data is transferred via fiber optic cables to the connected information, navigation, and communication components. The MOST operates with a transfer rate of 22 Mbits/s.

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The following control units are connected to MOST:

 Radio or COMAND

 CD player with changer (in glove compartment)

 Sound amplifier

 Hands-free system control unit

 Voice control system control unit

 SDAR control unit

 Audio gateway control unit

 Universal Portable CTEL Interface (UPCI [UHI]) control unit

Gateways:

The following control units form interfaces for the data exchange between MOST and other bus systems:

 Radio, COMAND or audio gateway control unit
(interface to CAN-B)

 Steering column module and instrument cluster

Although the instrument cluster and the steering column module are linked to both CAN-B and CAN-C, they are not used as an interface (gateway).